The present invention pertains to hydraulically powered equipment. More particularly, this invention relates to the use of a deceleration circuit for a hydraulic motor.
The invention finds particular application in hydraulic motors which are used to power mowers or ditchers or the like utilized in road maintenance equipment. However, it should be appreciated that the hydraulic motor deceleration system also finds application in other equipment in which a hydraulic motor is employed.
As is well known, hydraulically driven motors are currently utilized to power mowers, ditchers and like equipment especially equipment of the type that is secured to articulated boom assemblies pivotally connected to a tractor and used to maintain the berms of roads and the like. Currently, in such equipment, when hydraulic power is shut off to the motor, the motor, and with it the grass cutting blade or ditching blade which it drives, continues to freewheel (since the control valve of the motor generally has a motoring spool) when communication is interrupted between the hydraulic pump and the motor. If, on the other hand, a non-motoring spool were to be provided, the motor would come to a precipitous stop once the control valve would be actuated to the off position so that communication would be blocked between the hydraulic pump and the motor. Neither one of these alternatives is particularly desirable. When the motor is allowed to freewheel, it does not come to a stop very quickly and the cutting blade may damage something while the boom arm to which the blade housing is secured is being moved. On the other hand, if the motor and the blade would come to a rercipitous stop, great strains would be placed on the motor as well as the fasteners connecting the cutting blade to the motor and the blade would likely break its fasteners and fly off the motor.
Accordingly, it has been considered desirable to develop a new and improved hydraulic motor deceleration system which would overcome the foregoing difficulties and others by providing better and more advantageous overall results.